1. Field of the Invention
This invention relates to an intake unit. More particulary this invention relates to improvements in and concerning an air intake unit for an air conditioner in an automobile.
2. Description of Prior Arts
Generally, the air conditioner for use in the automobile mainly comprises an intake unit incorporating a blower, a cooler unit incorporating an evaporator and a heater unit incorporating a heater core. The air conditioner keeps the air inside the automobile comfortable for the driver and passengers by causing the intake unit to admit the air outside the automobile or the air inside the automobile or a mixture thereof, then the cooler unit to cool the incoming air, and the heater unit to heat or not to heat the whole or part of the cooled air as occasion demands and releases the air in the form of a draft of a desired temperature into the automobile interior.
When the climatic conditions under which the automobile equipped with the air conditioner is presently operated are varied notably from standard conditioner, the air conditioner conditions is required to have its construction altered to suit the particular climatic conditions. In the district in which the atmospheric temperature does not appreciably rise in the summer and no use is found for the cooler unit of the air conditioner, for example, the air conditioner in the automobile is more often than not supplied in the form of a car heater which leaves out a cooler unit and connects an intake unit 1 incorporating a blower 4 and a heater unit 3 incorporating a heater core 5 to each other with a heater duct 2 as illustrated in FIG. 1. In this case, the car heater is expected to keep the automobile interior in a comfortable atmosphere by allowing the air inside the automobile to be spontaneously ventilated by virtue of the ram pressure which is generated by the travel of the automobile. Unfortunately, the car heater has a disadvantage that the blower 4 which is at rest inside the blower section of the intake unit 1 offers resistance to the flow of air and consequently interferes with the spontaneous ventilation of the air inside the automobile. A solution of this disadvantage has been offered by a modified car heater which is provided with a duct outlet exclusively used for ram pressure ventilation so that the ambient air may be directly blown into the automobile interior without being passed through a blower, for example. This modified car heater, however, is incapable of utilizing the ram pressure except for the purpose of ventilation and also incapable of adjusting the outlet temperature of the incoming air. The practice of preparing intake units and outlets in constructions specially designed to suit varying climatic conditions under which automobiles equipped with car heaters are operated proves disadvantageous from the economic point of view because it fails to enjoy the merit of cost reduction due to mass production of parts of common use.